Fucking casuals.
Lanx
is the most correct on the jabs, it's actually called a flicker jab. The "palm strike" in this scenario isn't to gauge distance here. The distance is already dialed in, Wilder is backed into a corner and Fury has him in the pocket. The "palm strike" is a pawing jab used to pull down Wilders defenses and again block his vision for the next cross. This kind of jab has been used by several greats in boxing history like Tommy Hearns and Muhammad Ali.
1. Flicker jab feint
2. Flicker jab feint
3. Straight jab thrown intentionally short to "blind" Wilder from the next shot
4. Right cross
5. Pawing jab
6. Right cross
7. Pawing jab
8. Shovel hook
9. Left hook
All before Wilder even attempts to respond.
The use of a jab to "blind" your opponent is a pretty old technique that's criminally underused. Teddy Atlas describes it here.